#include "stm32f10x.h"                  // Device header

void PWM_Init(void){
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);

	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;
	GPIO_InitStructure.GPIO_Pin=GPIO_Pin_2;
	GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
	GPIO_Init(GPIOA,&GPIO_InitStructure);
  
    // 调整预分频器和周期，降低计数速度，方便观察
	TIM_InternalClockConfig(TIM2);
    TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
    TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInitStructure.TIM_Period = 100 - 1;  // 增大周期
    TIM_TimeBaseInitStructure.TIM_Prescaler = 720 - 1;  // 增大预分频
    TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);
    
	TIM_OCInitTypeDef TIM_OCInitStructure;
	TIM_OCStructInit(&TIM_OCInitStructure);
	TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_PWM1;
	TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High;
	TIM_OCInitStructure.TIM_OutputState=TIM_OutputState_Enable;
	TIM_OCInitStructure.TIM_Pulse=0; //ccr
	TIM_OC3Init(TIM2,&TIM_OCInitStructure);

	
    TIM_Cmd(TIM2, ENABLE);
}

void PWM_SetCompare1(uint16_t Compare){
	TIM_SetCompare1(TIM2,Compare);

}

void PWM_SetCompare3(uint16_t Compare){
	TIM_SetCompare3(TIM2,Compare);
}

void PWM_SetPrescaler(uint16_t Prescaler){
	TIM_PrescalerConfig(TIM2,Prescaler,TIM_PSCReloadMode_Immediate);
}
